President Trump gave North Korea a stern warning during his remarks before South Korea's National Assembly in Seoul on Nov. 7. (Melissa Macaya/The Washington Post)

President Trump on Wednesday warned against the threat posed by “a country ruled by a cult” in a hard-line speech aimed at rallying international pressure against North Korea over its escalating nuclear weapons program.

Trump, in an address to South Korea’s National Assembly, said the “rogue regime” was putting itself at risk by continuing to pursue its nuclear ambitions and test ballistic missiles. 

“The weapons you are acquiring are not making you safer,” Trump said, directing his remarks at North Korea. “They are putting your regime in grave danger. Every step you take down this dark path increases the peril you face.”

In a 35-minute speech here, for which he received a standing ovation, Trump offered a tough and blunt message to Pyongyang and dictator Kim Jong Un: “Do not underestimate us. And do not try us. We will defend our common spirit, our shared prosperity and our sacred liberty.”

But the president drew no red lines for what would prompt the United States to use military force, nor did he offer any additional ideas on how to coax North Korea to the negotiating table.

Nonetheless, Trump’s address framed the conflict on the peninsula in terms of dark — North Korea as “a hell that no person deserves” — versus light — South Korea as “a nation blessed with wealth, rich in culture, and deep in spirit.” He repeatedly heaped praise on his host country, holding up the nation as an affirming model for the North to follow. 

“The more successful South Korea becomes, the more decisively you discredit the dark fantasy at the heart of the Kim regime,” Trump said. “In this way, the very existence of a thriving South Korean republic threatens the very survival of the North Korean dictatorship.” 

Trump also made an emotional appeal, including on human rights, as he described, in searing detail, the brutal conditions in North Korea. He mentioned Otto Warmbier, the American student who sustained a severe neurological injury while imprisoned in North Korea and died shortly after his release to the United States.

In an apparent effort to press China to increase its pressure on Pyongyang, Trump recounted North Korean women being forced to abort or kill their babies if they are considered “ethnically inferior.”

“One woman’s baby born to a Chinese father was taken away in a bucket,” Trump said. “The guard said it did not deserve to live because it was impure.”

“So why,” he concluded, “would China feel an obligation to help North Korea?” 

The remarks came a day after Trump asserted that his administration is making “a lot of progress” on the Korean Peninsula and urged Kim to “make a deal” at the negotiating table on the rogue nation’s nuclear weapons and ballistic missile programs.

“I believe it makes sense for North Korea to do the right thing, not only for North Korea but for humanity all over the world,” Trump said during a joint news conference with South Korean President Moon Jae-in after a bilateral meeting at the Blue House.

“I do see certain movement, yes, but we’ll see what happens,” he added, without providing any details.

On Wednesday, Trump similarly expressed some willingness to work with North Korea, but only once it has committed to “complete, verifiable, and total denuclearization.”

“Yet despite every crime you have committed against God and man, you are ready to offer — and we will do that — we will offer a path to a much better future,” he said.

Trump’s slightly less bombastic remarks while on the Korean Peninsula were in marked contrast with some of his rhetoric back in the United States. The president has previously tried to antagonize North Korea, dubbing Kim “Little Rocket Man,” promising “fire and fury” if North Korea endangers the United States, and undercutting Secretary of State Rex Tillerson by tweeting that his top diplomat was “wasting his time” trying to negotiate with the regime.

On Tuesday, Trump praised Chinese President Xi Jinping, whom he will meet in Beijing for a three-day summit starting Wednesday, for being “very helpful” and added that China is “trying very hard to solve the problem.” He also offered hope that Russia will “likewise be helpful.”

Trump has said he expects to meet Russian President Vladimir Putin at a regional summit later in the week, either in Vietnam or the Philippines — one of the final stops on his 12-day trip to the Asia-Pacific region that began on Friday.

“This is not the right time to be doing it, but that’s what I got,” Trump said, complaining that his predecessors in the White House had failed to solve the North Korea issue. “This is a problem that should have been taken care of a long time ago.”

Before their news conference Tuesday, Trump and Moon — whose relationship is more distant than Trump’s friendships with Xi and Japanese Prime Minister Shinzo Abe — seemed to bond a bit. The two leaders took a “friendship walk” and dined together at a state dinner, complete with black tea blended with hydrangeas from the alpine region where South Korea will host its upcoming 2018 Winter Olympics. Moon also made a point of praising Trump for the upcoming anniversary of his Election Day victory.

Trump’s speech to the National Assembly might have taken on a different tenor — at least atmospherically — had the president not been thwarted in his plans for a “surprise” immediately before his address: An unannounced trip to the demilitarized zone between North and South Korea.

But foggy weather forced Trump’s helicopter to turn back, and he ultimately aborted the trip. Moon had been expected to join Trump at the border, in what White House press secretary Sarah Huckabee Sanders billed as a “historic moment” — the first time leaders of both the United States and South Korea would have visited the DMZ together.

The trip was kept under great secrecy, with Sanders alerting reporters traveling with the president to the surprise visit by holding up a piece of paper on which “DMZ” had been scrawled and announcing, “This is where we’re going.”

White House officials, at least publicly, had scrapped the idea of a trip to the DMZ before Trump left Washington — with one even describing it as “a little bit of a cliche” — but the president had repeatedly hinted at “a surprise” while in South Korea, and many aides privately said they didn’t think Trump would be able to resist a visit — and the ensuing photo opportunity.

Sanders said the trip had been planned since before Trump left for Asia, and that the president was disappointed and “pretty frustrated” that it didn’t work out.

But if Trump’s dramatic and symbolic gesture was thwarted, the president still managed some trademark flourishes. As he touted the virtues of South Korea in the opening portion of his speech Wednesday, he managed to plug his own golf course.

“In fact — and you know what I’m going to say — the women’s U.S. Open was held this year at Trump National Golf Club in Bedminster, N.J., and it just happened to be won by a great Korean golfer, Sung Hyun Park, and eight of the top 10 players were from Korea.”

The crowd, perhaps expecting a Trump-brand endorsement, laughed appreciatively and then clapped as the president concluded, “Now, that’s something. That is really something.”